Pregnanetriol is a metabolite of 17α-hydroxyprogesterone .1,2It is formed from 17α-hydroxyprogesterone by reduction of the C-20 ketone.2Urinary levels of pregnanetriol are elevated in patients with 21-hydroxylase deficiency and congenital adrenal hyperplasia.3,4 1.Kamrath, C., Hartmann, M.F., Boettcher, C., et al.Diagnosis of 21-hydroxylase deficiency by urinary metabolite ratios using gas chromatography-mass spectrometry analysis: Reference values for neonates and infantsJ. Steroid Biochem. Mol. Biol.15610-16(2016) 2.Schiffer, L., Barnard, L., Baranowski, E.S., et al.Human steroid biosynthesis, metabolism and excretion are differentially reflected by serum and urine steroid metabolomes: A comprehensive reviewJ. Steroid Biochem. Mol. Biol.194105439(2019) 3.Disorders of steroidogenesis guide to steroid profiling and biochemical diagnosis1(2019) 4.Shackleton, C.H.L.Role of a disordered steroid metabolome in the elucidation of sterol and steroid biosynthesisLipids47(1)1-12(2012)

N-Desethyl vardenafil is a metabolite of vardenafil , a phosphodiesterase 5 inhibitor, that is formed by the action of cytochrome P450 (CYP)3A4 and CYP3A5.

Desmethyl ranolazine is a metabolite of the antianginal agent ranolazine .1It is formed from ranolazine by the cytochrome P450 (CYP) isoform CYP3A. 1.Wang, Y., Chen, X., Sun, Z., et al.Development and validation of a sensitive LC-MS/MS assay for simultaneous quantitation of ranolazine and its three metabolites in human plasmaJ. Chromatogr. B889-89010-16(2012)

Febuxostat n-butyl isomer 是 Febuxostat 一种杂质。Febuxostat 是选择性黄嘌呤氧化酶 (XO) 抑制剂，Ki 为 0.6 nM。

Hydroxy ritonavir 是 Ritonavir 的代谢物。Ritonavir 是用于研究HIV 感染和 AIDS 的HIV 蛋白酶的抑制剂。

OSI-413 (free base) (CP 373413) 是Erlotinib的主要代谢产物。Erlotinib (CP-358774) 是一种直接作用于EGFR的酪氨酸激酶抑制剂，对人EGFR的 IC50为 2 nM。

Rivaroxabandiol是Rivaroxaban的代谢产物。Rivaroxaban是一种高效且选择性的凝血因子Xa (FXa) 直接抑制剂，其IC50为0.7 nM，Ki为0.4 nM。

PD 109488 is a metabolite of quinapril and is a derivative of Quinapril that acts as an ACE inhibitor. Inhibition of ACE prevents the conversion of signaling peptide angiotensin I into angiotensin II, which acts as a potent vasoconstrictor. Reduced levels of angiotensin II also reduces the amount of aldosterone that is expressed due to RAAS signaling.

(9E)-Erythromycin A oxime is a metabolite of the semisynthetic antibiotic roxithromycin .